Implementation of a Real Time High Level Protocol Software for Quantum Key Distribution

Quantum Key Distribution (QKD) guarantees the exchange of a perfect secure key between two parties exploiting the laws of quantum mechanics. Various QKD protocol have been proposed and all of them need a public communication in order to process the raw data and extract secure cryptographic keys. In this paper we present a real time JAVA implementation of the software needed to complete a quantum key distribution protocol. In particular we suggest a modified version of Cascade algorithm. An analysis of the problem is carried out by means of a Matlab simulator that we developed. The various steps, sifting, error correction and privacy amplification are discussed as well as the design choices including compatibility with various QKD protocols. A performances investigation with dedicated appliances is carried out in several operating conditions showing a strict relation between hardware and software implementation in terms of key rate.